SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ba11393c5d0334dd0133853677dba969c12a8c48011740fd32904e4098a67d9' 
  AND token = '5Y/egBawyNqNulxs9Os9osaAOnq4Io3Zz0my7m97+WM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}